What is a reasonable amount of alimony that I should be paying and for what length of time?

There are too many factors to consider to give you a response. See below family code regarding spousal support. - Factors To Be Considered In Ordering Support 4320 - In Ordering Spousal Support Under This Part, The Court Shall Consider All Of The Following In ordering spousal support under this part, the court shall consider all of the following circumstances: (a)The extent to which the earning capacity of each party is sufficient to maintain the standard of living established during the marriage, taking into account all of the following: (1)The marketable skills of the supported party; the job market for those skills; the time and expenses required for the supported party to acquire the appropriate education or training to develop those skills; and the possible need for retraining or education to acquire other, more marketable skills or employment. (2)The extent to which the supported party's present or future earning capacity is impaired by periods of unemployment that were incurred during the marriage to permit the supported party to devote time to domestic duties. (b)The extent to which the supported party contributed to the attainment of an education, training, a career position, or a license by the supporting party. (c)The ability of the supporting party to pay spousal support, taking into account the supporting party?s earning capacity, earned and unearned income, assets, and standard of living. (d)The needs of each party based on the standard of living established during the marriage. (e)The obligations and assets, including the separate property, of each party. (f)The duration of the marriage. (g)The ability of the supported party to engage in gainful employment without unduly interfering with the interests of dependent children in the custody of the party. (h)The age and health of the parties. (i)Documented evidence of any history of domestic violence, as defined in Section 6211, between the parties, including, but not limited to, consideration of emotional distress resulting from domestic violence perpetrated against the supported party by the supporting party, and consideration of any history of violence against the supporting party by the supported party. (j)The immediate and specific tax consequences to each party. (k)The balance of the hardships to each party. (l)The goal that the supported party shall be self-supporting within a reasonable period of time. Except in the case of a marriage of long duration as described in Section 4336, a reasonable period of time for purposes of this section generally shall be one-half the length of the marriage. However, nothing in this section is intended to limit the courts discretion to order support for a greater or lesser length of time, based on any of the other factors listed in this section, Section 4336, and the circumstances of the parties. (m)The criminal conviction of an abusive spouse shall be considered in making a reduction or elimination of a spousal support award in accordance with Section 4325. (n)Any other factors the court determines are just and equitable. Your marriage is one of long duration therefore the court will retain jurisdiction.

You are looking at approx 25k per year in permanent alimony unless you give her lump sum money to go away.

Alimony depends on FC 4320 factors not just income. With such a long marriage alimony could last until you retire she remarries or either one of you dies. You should see an attorney to discuss this.

There will be some but I need more details to estimate.